Spins in two-dimensional materials for tunable magnetic and optoelectronic devices

ongoing

In order for modern information technology to continue progressing at a rapid pace we require smaller devices consuming less energy. Magnetic materials provide a promising route for nonvolatile memory devices. However, downscaling them is challenging, and information transfer between devices is hindered by short spin relaxation lengths, making it necessary to convert spin information into charge currents, leading to an increase in power dissipation. The aim of this ERC project is to exploit the properties of two-dimensional (2D) materials to combine highly-efficient magnetic devices with optical communication. Specifically, I propose to seamlessly integrate the unique and highly efficient spin-orbit torques (SOTs) of 2D semimetals with the excellent optical properties of 2D semiconductors. Low-symmetry 2D semimetals present SOT symmetries not seen in conventional devices. These are ideal for the control of perpendicular magnetic anisotropy ferromagnets as used in modern high-density memory devices, with the added advantage of their small size. Due to their reduced dimensionality, 2D semiconductors show strong light-matter interaction, efficient electric control over their optical properties, and low lasing thresholds. When combined, energy-efficient devices can be realized in which nonvolatile magnetic information is optically transported over very large distances. To achieve this goal, I will (1) create externally controlled all-2D SOT devices, (2) realize electric tunability of spins and excitons in 2D semiconductors, (3) demonstrate electrical spin injection in a 2D semiconductor with spin direction controlled using SOTs, and (4) develop externally controlled 2D spin LEDs and spin lasers. This project will pave the way for new generations of information technologies, addressing fundamental aspects along the way. It will enrich the van der Waals spintronics field and provide a new strategy towards energy-efficient data storage and transport at the nanoscale.